Alloy intended for castings



Patented Nov. 4, 1924.

UNITED STATES PATENT OFFICE.

ALLOY INTENDED FOR CASTI'N'GS.

No Drawing.

To all whomit may concern:

Be it known that I, AMBROSE J ()SEPH h'IANDisLL, residing at 44 Jewel Street, Forest Hills, in the county of Queens, city and State of New York, and a citizen of the United States, have invented a new and useful Alloy Intended for Castings, of which the following is a specification.

The object of this invention is to provide an alloy which is intended for castings suitable for use at high temperature. My composition offers a very great resistance to oxidation at high temperatures. Most of the alloys heretofore used or proposed for the same purposes, contain chromium as an essential and indispensable ingredient. Chromium is an expensive ingredient and its elimination is a desirable object. In my composition, its elimination is made possible without impairing the efiicacy of the al loy. This, in itself, permits production of the alloy at a greatly decreased cost. Most of the prior alloys, because they necessarily contain chromium, flow sluggishly when molten. On the other hand, my composition, when molten, flows very freely. a property which is of great advantage in making castings. There are also castings which cannot be made with the alloys heretofore used or proposed, because their fluidity is not great enough. With my composition, it is practicable to make these latter castings, because of the ease with which the alloy flows when molten.

The essential ingredients of my alloy are nickel (or cobalt) and silicon. I have found that by addition of suitable amounts of silicon to nickel (or cobalt), that the resistance to oxidation is greatly increased and an alloy is produced which is very fluid when molten and of so high a resistance'to oxidation, that the addition of chromium or any other metal of the chromium group, in order to obtain this characteristic, is unnecessary. Moreover, the resistance to oxidation obtained by the addition of suitable amounts of silicon is so great, that it permits the addition of substantial amounts of iron to the alloy without so much lowering the resist-- J11) ance to oxidation of the resultant alloy,

as to impair its usefulness at high temperatures. The addition of iron does not impair the fluidity when molten, and when silicon is present to the amount of 5% or more in Appflication filed September 23, 1922.

Serial No. 590,086.

the finished alloy, the percentage of iron may beas much as by weight without impairing the usefulness, and without making it necessary to add chromium or any of the chromium group of metals, in order to increase the resistance of the alloy to oxidation.

A small percentage of aluminum, not to exceed3% by Weight of the finished alloy, is of some benefit, in that it tends to produce sounder castings and also to increase somewhat the resistance to oxidation. but when sufiicient silicon is present, no aluminum need be added. As regards the resistance to oxidation, aluminum may be used to replace a part of the silicon roughly weight for weight, but the total of aluminum in the alloy should not exceed 3%.

Small amounts of manganese may also be added to the alloy and are of some benefit, in that they increase the toughness of the product. This effect is obtained with additions up to 3%, but the addition of manganese up to 10% is not detrimental, although not of great benefit when the addition is greater than 3%.

Carbon may bepresent in the alloy in amounts not to exceed 2% without harm, but While it is impossible to keep the alloy entirely free from carbon, it should preferably be kept as low in carbon as possible.

In the reference in this specification and in the following claims to nickel, it is to be understood that cobalt is to be treated as an equivalent of and as a substitute for nickel in the alloy.

I claim:

1. An alloy intended for use in casting, composed predominantly of nickel with a materially less percentage ofsilicon.

2. An alloy for use in casting, comprising silicon in proportions of from 2% to 16% with the balance of nickel.

3. An alloy for use in casting, composed predominantly of nickel, with materially less percentages of silicon and iron.

4. An alloy for use in casting, composed predominantly of nickel, with materially less percentages of silicon and aluminum.

- 5. An alloy for use in casting, composed predominantly of nickel, with materially less percentages of silicon, iron and aluminum. I

AMBROSE JOSEPH MANDELL. 

